The invention relates to a path tracing apparatus for a robot, and in particular, to a path tracing apparatus for a robot which compares the actual path traced with the intended preset path.
A conventional path tracing apparatus employs a tracing method in which an intended path which is drawn on paper in advance is compared with an actual path which is duplicated on paper by a standard pen attached to the robot.
A conventional path tracing apparatus is illustrated in FIG. 1, which comprises a robot controller 20, a robot 30 which receives control data from the robot controller 20 for moving the robot 30, a standard pen 90 which is connected to the end ejector of the robot 30 and which is moved by the robot 30 so as to inscribe the path on paper 100.
In the above apparatus, the standard pen 90 is employed by the robot 30 to inscribe a path on paper 100. However, there is a problem due to the difficulty of producing an accurate copy of the path due to variations in the size of the penpoint and the quality of the paper.
Further, there is a problem in that an error evaluation comparing the intended path to be duplicated on the paper 100 with the actual path inscribed by the robot 30 must be measured by an additional measuring instrument. Also, because the intended path to be inscribed on paper is different in each kind of robot, the intended path for each kind of robot must be prepared in advance by being inscribed on paper.
Furthermore, another problem is that whenever the robot 30 repeats a move on the same track, the paper may need to be replaced with new paper to measure the deviation caused by the movement of the robot.